Home NodeB, which is one type of NodeB or evolved NodeB (eNodeB), i.e., a small low power NodeB, is deployed in private places such as homes, groups, companies or schools as the exclusive resources of private users. A main role of the home NodeB is to provide higher service rate for users, reduce expense required to use high-speed services and to make up for the deficiencies of coverage of the existing distributed cellular wireless communication system. Advantages of the home NodeB include veritable boon, conveniency, low power output, and plug and play.
Users of the home NodeB are connected to a core network via a Home NodeB Access Network (HNB AN for short), which consists of a Home NodeB (HNB for short) and a Home NodeB Gateway (HNB GW for short). Functions performed mainly by the home NodeB gateway include verifying security of the home NodeB, dealing with registration and access control of the home NodeB, performing operation, maintenance and management of the home NodeB, configuring and controlling the home NodeB according to requirements of operators, and being in charge of exchanging data between the core network and the home NodeB.
In the Universal Mobile Telecommunications System (UMTS for short), the home NodeB must access to the core network via the home NodeB gateway. An interface between the home NodeB and the home NodeB gateway is an Iuh interface, and an interface between the home NodeB gateway and the core network is an Iu interface.
In the Long Term Evolution (LTE for short) system, a home evolved NodeB (HeNB) may be connected to the core network directly without through the home NodeB gateway. If the home NodeB gateway exists, interfaces both between the home NodeB and the home NodeB gateway and between the home NodeB gateway and the core network are S1 interfaces. Protocol stack of the S1 interface is divided into a control plane and a user plane.
Home NodeBs in the LTE and UMTS systems access to a H(e)NB Management System (HMS for short), which is in charge of the management and configuration of the home NodeB, based on the TR-069 protocol stack.
A plurality of cells covered by the home NodeB constitutes a coverage area of the home NodeB. Access modes of the home NodeB include a closed access mode, hybrid access mode and open access mode. A home NodeB with the closed access mode only allows access of authorized users, such as family members and group members. A home NodeB with the hybrid access mode allows access of all users, but the authorized users of the home NodeB enjoy priority or preferential conditions. A home NodeB with the open access mode allows access of all users.
The Closed Subscriber Group (CSG for short) cell has not only a Cell Global Identifier (CGI) but also a CSG cell identifier (CSG ID). CSG cells possessing different cell global identifiers may correspond to the same CSG ID. A home NodeB gateway or a core network element connected to the home NodeB may acquire, at an initialization stage of the home NodeB, the CSG ID and the access mode of the home NodeB, as well as the cell global identifier of the cell in which the home NodeB is set up. A non-home NodeB is generally referred to as a NodeB or macro NodeB, and its cell is referred to as a macro cell. With the constant promotion of discussion of the technology, the CSG concept is applied to not only the home NodeB but also the macro NodeB so as to perform access control for the users.
To implement access control required for the aforementioned three different access modes, standard organizations introduced the CSG concept. Since a user joins a specific CSG and the cell in which the home NodeB is set up is endowed with logic CSG attributes (including the CSG ID), the core network, the home NodeB and the home NodeB gateway collectively complete control of the access user. When a user equipment (UE for short) wants to reside in a CSG cell with the closed or hybrid mode, the home NodeB reports the CSG ID of the cell and the access mode to the network side, which checks whether the UE is a member of the CSG based on communication context and subscription data of the UE. For a CSG cell with the closed mode, only access of an authorized user is allowed (the UE becomes an authorized user as soon as it becomes a member of the CSG), and access of the unauthorized users is prohibited. For a CSG cell with the hybrid mode, the network side will allow access of an applying user, while notifying the home NodeB of information as to whether the user is a member of the CSG. The home NodeB will perform admission and management of priority or preference for the member. A home NodeB with the open mode behaves like a common macro NodeB and can perform direct access rather than CSG-based access control.
There are two approaches for a UE to enter a cell, one is to directly access to a target cell, and the other is to switch to a target cell from other cells through a handover mode. In the handover process of the UE, signaling interaction may be performed via an interface between a Radio Network Controllers (RNC)/NodeB and a core network or via a direct interface between RNCs or between NodeBs. However, when the UE performs handover via a direct interface between a source access network element and a target access network element, there is no implementation method for access control in the existing technology.